Early Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation: A Comparison of Titanium-Coated Polyetheretherketone Cages and Carbon Polyetheretherketone Cages

STUDY DESIGN: Retrospective cohort study. PURPOSE: We recently reported that when compared to posterior lumbar interbody fusion (PLIF) using traditional pedicle screw fixation, PLIF with cortical bone trajectory screw fixation (CBT-PLIF) provided favorable clinical outcomes and reduced the incidence of symptomatic adjacent segment pathology, but resulted in relatively lower fusion rates. Since titanium-coated polyetheretherketone (PEEK) cages (TP) could improve and accelerate fusion status after CBT-PLIF, early fusion status was compared between CBT-PLIF using TP and carbon PEEK cages (CP). OVERVIEW OF LITERATURE: A systematic review demonstrated that clinical studies at this early stage show similar fusion rates for TP compared to PEEK cages. METHODS: We studied 36 consecutive patients undergoing CBT-PLIF with TP (TP group) and 92 undergoing CBT-PLIF with CP (CP group). On multiplanar reconstruction computed tomography (MPR-CT) at 6 months postoperatively, vertebral endplate cysts (cyst signs) were evaluated and classified as diffuse or local cysts. Early fusion status was assessed by dynamic plain radiographs and MPR-CT at 1 year postoperatively. RESULTS: The incidences of cyst signs, diffuse cysts, and early fusion rate in the TP and CP groups were 38.9% and 66.3% (p0.05), respectively. Combining the two groups, 22 of 36 patients with diffuse cysts had nonunion at 1-year follow-up, compared to only three of 92 patients with local cysts or without cyst signs (p<0.01). CONCLUSIONS: Despite having fewer patients with endplate cysts at 6 months (a known risk factor for nonunion), the TP group had the same fusion rate as the CP group at 1-year follow-up. Thus, TP did not accelerate the fusion process after CBT-PLIF.

Usefulness of Anterior Cervical Interbody Fusion Using Locally Harvested Bone: Minimum 5-Year Follow-Up / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to determine the usefulness of locally harvested autobone as a filling material for fusion. MATERIALS AND METHODS: Retrospective study was conducted for 21 patients diagnosed as cervical disc herniation with cervical myelopathy or radiculopathy who underwent anterior cervical fusion using locally harvested autobone and polyetheretherketone solis cage from June 2006 to September 2009, with a follow-up period of longer than 5 years. Radiologic outcomes were evaluated by the rate of bone union, the change of intervertebral height, and the subsidence of the cage. RESULTS: In clinical results, visual analogue scale score was 5.8±0.71/7.7±0.78 at preoperative, 1.6±0.58/2.3±0.97 at 1-year follow-up, 1.8±0.81/2.7±1.28 at 5-year follow-up, and neck disability index score was 34.3±6.2 in preoperative stage, 6.25±3.21 at 1-year follow-up, and 6.51±4.05 at 5-year follow-up. Radiologically intervertebral height was reduced from average 6.31±0.93 mm in 1-year follow-up to average 6.22±0.85 mm in 5-year follow-up. Subsidence of cage was average 1.28±0.41 mm at 1-year follow-up and average 1.31±0.43 mm at 5-year follow-up, with no statistically significant difference (p>0.05). Average subsidence of cage in these cases was 3.25 mm. In postoperative complication, screw breakage occurred in 1 case, screw pull out occurred in 1 case, and there was no postoperative infection. CONCLUSION: Using locally harvested autobone as filling material for fusion resulted in outstanding bone union and improvement of clinical results. In long term follow-up, there was no significant difference in union rate and complication incidence. Therefore use of locally harvested autobone as a filling material for fusion is considered an effective method.

A Prospective Randomized Clinical Trial Comparing Bone Union Rate Following Anterior Cervical Discectomy and Fusion Using a Polyetheretherketone Cage: Hydroxyapatite/B-Tricalcium Phosphate Mixture versus Hydroxyapatite/Demineralized Bone Matrix Mixture

STUDY DESIGN: Prospective randomized noninferiority trial. PURPOSE: To evaluate whether the union rate of anterior cervical discectomy and fusion (ACDF) using a polyetheretherketone (PEEK) cage filled with a mixture of hydroxyapatite (HA) and demineralized bone matrix (DBM) is inferior to that of a mixture of beta-tricalcium phosphate (beta-TCP) and HA. OVERVIEW OF LITERATURE: There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF. METHODS: Eighty-five eligible patients were randomly assigned to group B (n=43), in which a PEEK cage with a mixture of HA and DBM was used, or group C (n=42), in which a PEEK cage with a mixture of HA and beta-TCP was used. The primary study endpoint was the fusion rate, which was assessed with dynamic radiographs and computed tomography (CT) scans. Secondary endpoints included pain intensity using a visual analogue scale, functional outcome using a neck disability index score, laboratory tests of inflammatory profiles, and the infection rate. RESULTS: Seventy-seven patients (38 in group B and 39 in group C) were included in the final analysis. One year postoperatively, bone fusion was achieved in 87% of group B patients and 87% of group C patients on dynamic radiographs, and 87% of group B patients and 72% of group C patients on CT scans (p=1.00 and 0.16, respectively). There were also no between-groups differences with respect to the secondary endpoints. CONCLUSIONS: A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF.

Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage

OBJECTIVE: The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. METHODS: A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. RESULTS: During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (> or =7mm) (p=0.037) were significantly associated with subsidence. CONCLUSION: The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (> or =7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages.

Late Results of Anterior Cervical Discectomy and Fusion with Interbody Cages

STUDY DESIGN: Retrospective analysis. PURPOSE: To evaluate the effectiveness of anterior cervical discectomy with fusion for degenerative cervical disc disease. OVERVIEW OF LITERATURE: Anterior spinal surgery originated in the mid-1950s and graft for fusion was also employed. Currently anterior cervical microdiscectomy and fusion with an intervertebral cage is a widely accepted procedure for treatment of cervical disc hernia. Artificial grafts and cages for fusion are preferred because of their lower morbidity, reduced operating time and acceptable fusion rate. METHODS: The study involved retrospective analysis and investigation of long-term results for 41 consecutive patients who had undergone anterior cervical discectomy and fusion with an intervertebral cage for cervical disc hernia. The angle of lordosis, segmental height and range of motion were evaluated preoperatively and postoperatively at 1 month and 2 years. The clinical outcome was assessed by the visual analog scale and Odom's criteria. RESULTS: The angle of lordosis increased by 2.62degrees and the range of motion angle increased by 5.14degrees after the operation. The segmental height did not change. The visual analog scale and Odom's criteria scores decreased significantly after the operation. CONCLUSIONS: Using a cage in anterior cervical discectomy prevents segmental collapse, so the segmental height and the angle of lordosis are preserved and newly-developed pain does not occur.

New Cervical Laminoplasty Polyethererketone Cage: Two Case Reports

Cervical laminoplasty is a widely used technique to enlarge the spinal canal for spinal cord decompression. The two common methods are an open door laminoplasty and a midline splitting laminoplasty. Several devices and materials have been used as a spacer for maintaining or stabilizing the lamina in the open or split position, however, some are difficult to implant. Moreover, they are not designed to restore the natural dynamics of the cervical spine, and can cause discomfort to the patient. There is a need to develop a device and material that will be effective in maintaining and stabilizing the position of the lamina after laminoplasty, being able to be implanted easily and safely to restore the natural dynamics of the cervical spine, as well as getting the bony union to the host bone. We report two cervical laminoplasty patients who were treated using a new laminoplasty polyetheretherketone cage.